New Record of Derolathrus Cavernicolus (Coleoptera: Jacobsoniidae) from Japan

Japanese Journal of Systematic Entomology, 26 (2): 206–207. December 30, 2020.

New record of Derolathrus cavernicolus (Coleoptera: Jacobsoniidae) from Japan

Hiroyuki YOSHITOMI 1) and Yu HISASUE 2) 1) Ehime University Museum, Bunkyo 3, Matsuyama, 790-8577 JAPAN [email protected] 2) Entomological Laboratory, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka, Fukuoka, 819-0395, JAPAN [email protected]

Abstract Derolathrus cavernicolus Peck, 2010 is recorded from Shikoku and Iriomote-jima, Japan. This is the first formal report of the family Jacobsoniidae from Japan.

The genus Derolathrus Sharp, 1908 is represented by also provided. eight extant and two fossil species from mainly tropical Morphological abbreviations are as follows: EL = sutural areas and oceanic islands (Yamamoto et al., 2017). In Japan, elytral length; EW = maximal elytral width; HL = head length; “Derolathrus atomus ?” was reported from Ogasawara (Haha- HW = head width including eyes; PL = mesal pronotal length; jima) and Minami-Iwo-To (Ueno, 1998; Mori et al., 2018; PW = maximal pronotal width; TL = total length (HL + PL + Kishimoto et al., 2018), and one specimen of Derolathrus EL). The average is given in parentheses after the range. sp. was collected from Kita-Daito-jima (Hirano in private communication). Derolathrus cavernicolus Peck, 2010 We found two specimens of Derolathrus sp. collected from Shikoku and Iriomote-jima are preserved in the Specimens examined. 1 ex. (Fig. 1, probably male, collection of Ehime University Museum (EUMJ). After a EUMJ), “RYÛKYÛ; JAPAN / Is. Iriomote / Shirahama-rindou close examination, it is concluded that these specimens are / 13. III. 1999 / Tatsuya Kan leg.”; 1 ex. (Fig. 2, probably Derolathrus cavernicolus Peck, 2010. In this paper we record female, EUMJ), “ 愛媛県松山市食場町 / 33°51'39.2’’N, this species from Shikoku and Iriomote-jima, Japan. This is 132°49'40.8’’E / Jikiba-machi, Matsuyama-shi / Ehime Pref., the first report based on identified specimens of the family Shikoku, JPN, 17-VI-2017 / Tullgren, Yu HISASUE leg.”. Jacobsoniidae from Japan. A key to species of the genus is Measurements and ratios. TL 910–980 (945) μm; HL

Figs. 1–2. Habitus of Derolathrus cavernicolus Peck, 2010. 1, Specimen from Iriomote-jima; 2, specimen from Ehime. Scale = 500 μm.

180–190 (185) μm; HW 190–204 (197) μm; PW 190–210 ...... †D. abyssus Yamamoto (200) μm; PL 200–240 (220) μm; EL 520–560 (540) μm; et Parker, 2017 (Burmese amber, Upper Cretaceous) EW 280–300 (290) μm; HL/HW 0.88–1.00 (0.94); PW/PL 5’. Abdominal tergite VII invisible dorsally...... D. 0.88–0.95 (0.91); EL/EW 1.86–1.87 (1.86); EL/PL 2.33–2.60 cavernicolus Peck, 2010 (USA, Hawaii, Barbados, Japan) (2.47); EW/PW 1.43–1.47 (1.45); TL/EW 3.25–3.27 (3.26). Remarks. We determine the species by the following key Acknowledgments to species. We thank Mr. Tatsuya Kan for providing precious Distribution. USA (Florida, Alabama, Hawaii), Barbados, specimen and the late Mr. Yukihiko Hirano, Dr. Shuhei Japan (Shikoku, Iriomote-jima). Yamamoto, and Dr. Toshio Kishimoto for their kind support in Biological notes. Both specimens from Japan were literature and information. collected from leaf litter in subtropical natural forest (Iriomote-jima) and temperate secondary forest (Shikoku). In Florida and Barbados, many specimens were collected from References insectivorous bat guano in caves (Peck, 2010). Cai, C.-Y., R. A. Leschen, Y. Liu, and D.-Y. Huang, 2016. First fossil jacobsoniid beetle (Coleoptera): Derolathrus groehni n. Key to species of the genus Derolathrus sp. from Eocene Baltic amber. Journal of Paleontology, 89: 762–767. (modified after Peck, 2010; Yamamotoet al., 2017) Kishimoto, T., T. Sasaki, and S. Wada, 2018. Preliminary study of soil macrofauna on Minami-Iwo-To Island. Ogasawara 1. Eyes smaller, their diameter less than distance from their Research, (44): 295–304. (In Japanese, with English title and anterior margin to base of antennae. ...D. troglophilus summary.) (Sen Gupta, 1979) (Fiji), D. parvulus (Rücker, 1983) Mori, H., H. Karube and T. Kishimoto, 2018. Insect fauna on (Madaeira), D. anophthalmus (Franz, 1969) (Canary Isls.), Minami-Iwo-To Island. Ogasawara Research, (44): 251–288. D. sharpi Grouvelle, 1912 (Lesser Antilles, Virgin Isls.) (In Japanese, with English title and summary.) 1’. Eyes larger, their diameter greater than the distance from Peck, S. B., 2010. Derolathrus cavernicolus n. sp., a beetle family their anterior margin to base of antennae...... 2 new for North America (Coleoptera: Jacobsoniidae). Annales 2. Pronotum lacking a longitudinal groove...... of the Entomological Society of America, 103: 1–6. Ueno, T., 1998. Enigmatic coleopteran family Jacobsoniidae ...... D. atomus Sharp, 1908 (Hawaii, West Indies) discovered from Japan, with its morphological evidence on 2’. Pronotum with a longitudinal groove...... 3 actively moving as ‘aeroplankton’. Program and abstract of 3. Antenna with 1-segmented club...... the 58th Annual Meeting of the Entomological Society of ...... D. insularis (Dajoz, 1973) (Mauritius), †D. Japan, p. 106. (In Japanese.) groehni Cai et al., 2016 (Baltic amber, middle Eocene) Yamamoto, S., Y. Takahashi, and J. Parker, 2017. Evolutionary 3’. Antenna with 2-segmented club...... 4 stasis in enigmatic jacobsoniid beetles. Gondwana Research, 4. Pronotum elongate, more than 1.5 times as long as wide. 45: 275–281...... D. ceylonicus (Sen Gupta, 1979) (Sri Lanka) 4’. Pronotum oblong-oval, slightly longer than wide. ...5 [Received: August 27, 2020; accepted:October 31, 2020] 5. Abdominal tergite VII exposed from elytral apex......

December 30, 2020, JJSE 26 (2)